A multiplexer is configured on a programmable logic device using a plurality
of
four-input look-up tables chained together. The required number of look-up tables
is about one-half the number of inputs of the multiplexer. For an even number of
inputs, the number of look-up tables preferably is exactly one-half the number
of inputs, while for an odd number of inputs, the number of look-up tables preferably
is one-half the number of inputs, plus one-half. The number of control inputs preferably
is one more than the number of look-up tables. Preferably, for any one input being
a given logic state, and further selected by the one extra input (beyond the number
of look-up tables), any particular output may be asserted.